Return of the twaite shad to the Scheldt River After a Century-Long Absence

The twaite shad's recovery highlights the improvement in water quality in the Scheldt, which had once been heavily polluted. Today, populations can be found in both the Scheldt and Rupel rivers, though historical spawning grounds around Lier are still unoccupied. Volunteers, coordinated by INBO and Natuurpunt, are monitoring spawning sites.

The research team, operating from a pontoon, uses fyke nets to catch the fish, which are then tagged for further tracking. In addition, the growth rings on their scales are analyzed to determine their age and spawning history. The team has discovered that the twaite shad exhibits "homing behavior," with 40% of the fish returning to spawn in the Scheldt. However, there are still many unknowns, such as the twaite shad’s winter habitat and the full extent of its migratory routes.

This research is crucial for protecting the twaite shad, a species that requires cross-border conservation efforts, as it migrates beyond national boundaries. Despite challenges, the return of the twaite shad in Belgium is a rare success story, as the species continues to decline in other European countries.

Press (in Dutch): DE FINT IS TERUG VAN WEGGEWEEST (p. 8)